[BANGKOK] Experts have warned that Asian governments are underestimating the threat of the region's slowly-evolving HIV epidemics, and are not implementing adequate strategies to prevent transmission of the virus.
Speaking at the opening ceremony of the 15th International Conference on AIDS in Bangkok on Sunday (11 July), Tim Brown, senior research fellow at the US-based East West Centre, said that a slowly developing epidemic is a cause for concern as "it flies below the radar".
Reports by Brown and Karen Stanecki, from the US Bureau of Census's Centre for International Research, have indicated that HIV/AIDS has spread in a broadly similar way within individual Asian countries. The disease first affects injecting drug users (IDUs) and homosexual men. Then, two or three years after this, HIV begins to spread from IDUs to sex workers, and to sex workers' clients. Rates of infection then grow among pregnant women, and in the next generation as a result of mother-to-child transmission.
Despite the similarities across separate Asian countries, the region's epidemic has been characterised by an "incredible diversity" in speed and severity from country to country, said Brown. According to his team's latest modelling studies, Asian nations now fall into three groups.
In the first cluster are countries that experienced early and fast-growing epidemics in the late 1980s. These include Cambodia, Myanmar and Thailand, as well as several Indian states – their HIV levels now exceed one per cent of the adult population.
The second group includes much of China, Indonesia, Nepal and Vietnam, where the onset of an HIV/AIDS epidemic was delayed until the mid-1990s. HIV infection levels in these regions are less than 0.5 per cent of the population.
Countries in the third group, which includes Bangladesh, Japan, Laos and the Philippines, have yet to see an extensive spread of HIV.
Brown's models predict that over one per cent of adult males and 0.2 per cent of adult females in Asia could be infected with HIV by 2010. These numbers are predicted to rise to almost five per cent of men and two per cent of women by 2030.
The late take-off and slow growth of many Asian epidemics and the absence of extensive HIV infection in some countries is no proof of "national immunity", warned Brown. Though some countries currently appear to have a low prevalence of HIV, inadequate prevention strategies may mean that the epidemic will spread rapidly in a few years, he said.
Accordingly, Karen Stanecki's data shows that in Jakarta, Indonesia, HIV infection rates have risen sharply, from almost ten per cent of IDUs in 1998 to almost 50 per cent in 2003. Following this, the disease spread rapidly to sex workers, where infection rates went from zero per cent in 1999 to nearly ten per cent in 2003. Data from the Joint United Nations Programme on HIV/AIDS indicates that 70 per cent of male IDUs have unprotected sex with commercial sex workers.
Brown cited Thailand as an example of how focused prevention strategies can significantly reduce infection rates. Almost 90 per cent of Thai sex workers now use condoms and the number of men visiting sex workers has halved. As a result, infection rates in Thailand have fallen from over 140,000 in 1991 to just over 21,000 this year.
Cambodia has also reported a similar rise in the number of condom users and decline in HIV infection rate between 1998 and 2003. But most Asian countries lag behind. In Bangladesh, China and Indonesia, condom use remains low.Speaking to journalists, Brown predicted a rapid growth of the epidemic in the next two to three years in Bangladesh, and in China, where ten per cent of men visit sex workers.